The classpathx mail-1.1.2 package does not implement this properly. As a result, the initial dot on a line gets deleted by the receiving SMTP server.

This is particularly a problem when using Content-Transfer-Encoding: quoted-printable because this wraps lines to 76 characters using soft carriage returns; this may force dots to the beginning of a line. This encoding is used when the message has MIME-type text/html.